Title

Kubernetes Kubelet must deny hostname override. (Cat II impact)

Discussion

Kubernetes allows for the overriding of hostnames. Allowing this feature to be implemented within the kubelets may break the TLS setup between the kubelet service and the API server. This setting also can make it difficult to associate logs with nodes if security analytics needs to take place. The better practice is to setup nodes with resolvable FQDNs and avoid overriding the hostnames.

Check Content

On the Kubernetes Control Plane and Worker nodes, run the command: ps -ef | grep kubelet Check the config file (path identified by: --config): Change to the directory identified by --config (example /etc/sysconfig/) run the command: grep -i hostname-override kubelet If any of the nodes have the setting "hostname-override" present, this is a finding.

Fix Text

Edit the kubelet file on each node under the --config directory and remove the hostname-override setting. Reset Kubelet service using the following command: service kubelet restart

Additional Identifiers

Rule ID: SV-242404r879586_rule

Vulnerability ID: V-242404

Group Title: SRG-APP-000133-CTR-000290

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.